Laburnumanagyroidis – golden chain-treeDistribution: Occurring chiefly west of the Cascades crest at low elevations in Washington; British Columbia south to California, Utah.Habitat: Disturbed sites often in proximity to residential development where escaped from cultivation.Origin: IntroducedFlowers: May-June

Lactucabiennis – tall blue lettuce, wild blue lettuceDistribution: Alaska to Newfoundland, south to California and North Carolina.Habitat: Moist places.Origin: NativeFlowers: July - August

Lactucacanadensis – Canadian wild lettuce, Florida blue lettuceDistribution: Widespread in eastern United States; occasionally introduced in the Pacific Northwest.Habitat: Fields, woodlands and waste places.Origin: Introduced from eastern North AmericaFlowers: July - September

Lactucasaligna – least lettuce, willow lettuceDistribution: Occurring in scattered locations in Washington; Washington south to California, east across the southwestern U.S. to the central U.S. and northeastern North America.Habitat: Disturbed areas, roadsides, and meadows.Origin: IntroducedFlowers: August-October

Lactucasativa – garden lettuceDistribution: Occurring in scattered locations in Washington; Washington south to California, east to Idaho; in scattered locations in the central U.S., more commonly distributed in eastern North America.Habitat: Disturbed areas, often escaping from cultivation.Origin: IntroducedFlowers: July-September

Lactucaserriola – prickly lettuceDistribution: Occurring on both sides of the Cascades in Washington; common and widespread throughout much of North America.Habitat: Fields and waste places.Origin: Introduced from EuropeFlowers: July-September

Lactucavirosa – great lettuce, tall lettuce, wild lettuceDistribution: Known from Puget Trough region in Washington; also in California, Mississippi, and Maryland.Habitat: Disturbed, open areas at low elevations including wastelots and roadsides.Origin: IntroducedFlowers: May-October

Ladeanialanceolata – wild lemonweed, lance-leaf scurf pea, scurf-peaDistribution: East of the Cascades in Washington, mostly in the central and southcentral areas of the state; Washington south to California, east to the central regions of Canada and the U.S.Habitat: Sagebrush steppe habitat in dry areas, often where sandy.Origin: NativeFlowers: May-June

Lagophyllaramosissima – slender hareleaf, common rabbitleafDistribution: Occurring east of the Cascades in Washington; Washington south to California, east to Montana, Idaho, and Nevada.Habitat: Dry, open areas of foothills and plains.Origin: NativeFlowers: May-July

Lamiastrumgaleobdolon – yellow archangelDistribution: West of the Cascades in Washington; California and scattered localities in eastern U.S.Habitat: Introduced as an ornamental, escaping in lowland forest understory and disturbed soil in shaded areas.Origin: Introduced from EurasiaFlowers: May-June

Lamiumamplexicaule – common dead-nettle, giraffeheadDistribution: Both sides of the Cascades in Washington; introduced and widespread in North America; Eurasia and North Africa.Habitat: Weed in distrurbed areas, fields, lawns.Origin: Introduced from EurasiaFlowers: April-July

Lamiumpurpureum – red dead-nettle, henbitDistribution: Both sides of the Cascades in Washington, but more common on the west side; introduced throughout North America.Habitat: Weed in distrurbed areas, fields, lawns at lower elevations.Origin: Introduced from EurasiaFlowers: April-July

Lappulalongispina – long-spined stickseedDistribution: East of the Cascades in the Pacific Northwest; Eurasia.Habitat: A weed in dry, disturbed places, along roadsides and on overgrazed ranges.Origin: IntroducedFlowers: May - July

Lapsanacommunis – common nipplewortDistribution: Occurring on both sides of the Cascades crest in Washington, but more often west of the crest; BC to CA, scattered elsewhere in western North America, and more common in central and eastern North America.Habitat: Disturbed areas including roadsides, wastelots, fields, and forest edge.Origin: Introduced from EurasiaFlowers: June-July

Larixlyallii – subalpine larchDistribution: Occurring chiefly east of the Cascades crest in Washington; southern British Columbia to the central Cascades and Wenatchee Mountains in Washington, east to Montana and Alberta.Habitat: Generally near timberline, preferring north-facing slopes.Origin: NativeCones: June-July (cone production)

Larixoccidentalis – western larchDistribution: East of the Cascades, British Columbia to Oregon, east to Montana and AlbertaHabitat: Mountain valleys and lower slopes, often in swampy areasOrigin: NativeCones: May - June

Lathyrusaphaca – yellow vetchlingDistribution: Known only from the San Juan Islands in Washington; Washington south to California, and in scattered locations in central and southern U.S.Habitat: Disturbed ground.Origin: IntroducedFlowers: May-July

Lathyrusjaponicus – beach peaDistribution: Coastal in Washington; Alaska south to California; also along the Atlantic Coast.Habitat: Sandy beaches, dunes, and headlands along the coast.Origin: NativeFlowers: May-September

Lathyruslanszwertii – Nevada peavine, thick-leaved peavineDistribution: Occurring chiefly east of the Cascades crest in Washington; Washington south to California, east to Idaho and Utah.Habitat: Sagebrush-ponderosa pine woodland to moderate elevations in the mountains.Origin: NativeFlowers: May-June

Lathyruslatifolius – everlasting-peaDistribution: Occurring in locations throughout much of Washington; widespread in North America.Habitat: Found in a variety of disturbed habitats, usually where somewhat moist.Origin: IntroducedFlowers: May-July

Lathyrusnevadensis – Sierra peavineDistribution: Occurring on both sides of the Cascades crest and in the southeast corner of the State; British Columbia south to California, east to Idaho.Habitat: Open woods at moderate to mid-elevations.Origin: NativeFlowers: May-July

Lathyrusochroleucus – cream peaDistribution: Occurring east of the Cascades crest along the northern border in Washington; Alaska south to Washington, east across the northern U.S. and Canada to the Atlantic Coast.Habitat: Moist woods, at the edge of thickets.Origin: NativeFlowers: May-July

Lathyruspalustris – marsh peaDistribution: Occurring along the Puget Sound and outer coast in Washington; widely distributed throughout most of North America except the Rocky Mountain and southeastern regions of the U.S.Habitat: Chiefly in tidelands along the coast.Origin: NativeFlowers: April-July

Lathyruspauciflorus – few-flowered peavineDistribution: Occurring chiefly east of the Cascades crest in Washington;, Washington, south to California, east to Idaho and Arizona.Habitat: Shrub-steppe to Ponderosa pine and higher open forests.Origin: NativeFlowers: April-June

Lathyruspolyphyllus – leafy peaDistribution: Occurring west of the Cascades crest in lowland Washington, and east up the Columbia River Gorge; Washington south to California.Habitat: Prairies and open areas of low mountains.Origin: NativeFlowers: May-July

Lathyrustorreyi – Torrey's peaDistribution: Occurring west of the Cascades crest in Washington; Washington south to California.Habitat: Open prairies and clearings in the woods at low elevations.Origin: NativeFlowers: May-July

Layiaglandulosa – white layia, white daisy tidytipsDistribution: Occurring chiefly east of the Cascades crest in Washington; southern British Columbia south to California, east to Idaho, Utah, Arizona and New Mexico.Habitat: Dry, open places in the deserts and foothills.Origin: NativeFlowers: April-June

Leersiaoryzoides – rice cut grassDistribution: Occurring on both sides of the Cascades in Washington; British Columbia east to the Atlantic Coast, south throughout the U.S.Habitat: Wet places, often in fairly deep water.Origin: NativeFlowers: July-September

Lemnaminor – common duckweed, lesser duckweed, water lentilDistribution: Cosmopolitan in temperate and subtropical regionsHabitat: In standing or slow-moving fresh waterOrigin: NativeFlowers: June - October

Lemnatrisulca – ivy duckweed, ivy-leaved duckweed, star duckweedDistribution: Throughout much of the temperate and subtropical regions of the world.Habitat: Quiet streams and standing fresh water.Origin: NativeFlowers: July - September

Leontodonautumnalis – autumn hawkbitDistribution: Known from San Juan and Whatcom counties in Washington; Alaska to Oregon, east to Idaho and Montana; also in eastern North America.Habitat: Roadsides, pastures, open fields and other disturbed areas primarily in the lowlands, but also found along roads at alpine elevations in the mountains (e.g., Mt. Baker area).Origin: Introduced from EurasiaFlowers: July-September

Leontodonsaxatilis – hairy hawkbitDistribution: Occurring in scattered locations in Washington, chiefly west of the Cascades crest; British Columbia south to California, Nevada, and Arizona; central and eastern U.S.Habitat: Disturbed sites.Origin: IntroducedFlowers: July-September

Leonuruscardiaca – motherwort, Lion's tailDistribution: Scattered location in Washington; found occasionally in North America.Habitat: Disturbed ground, often in association with cities and towns.Origin: Introduced from EurasiaFlowers: June-September

Lepidiumappelianum – globepodded hoarycress, whitetopDistribution: Widely distributed throughout many areas in Washington, though more common east of the Cascades crest; widely distributed throughout much of North America.Habitat: Disturbed soil, waste areas, in dry and moist places.Origin: Introduced from AsiaFlowers: April-August

Lepidiumcampestre – field cress, field peppergrass pepperwortDistribution: Distributed across Washington in scattered locations; distributed throughout much of North America.Habitat: Dry, disturbed areas.Origin: Introduced from EurasiaFlowers: May-July

Lepidiumchalepense – chalapa hoarycress, lens-podded hoarycress, Asian white-topDistribution: Occurring east of the Cascades crest in Washington; widely distributed throughout much of North America.Habitat: Disturbed areas, especially where dry, often associated with agriculture.Origin: Introduced from AsiaFlowers: May-June

Lepidiumdictyotum – alkali peppergrass, veiny peppergrassDistribution: Occurring east of the Cascades crest in Washington; Washington south to California, east to Idaho, Nevada, and Utah.Habitat: Open areas often where seasonally moist, such as vernal ponds; tolerant of alkaline soils.Origin: NativeFlowers: April-May

Lepidiumdidymum – lesser swinecress, lesser wartcressDistribution: Occurring west of the Cascades crest in Washington; British Columbia south to California and Arizona, and Texas eastward and northward to the Atlantic Coast.Habitat: Roadsides, gardens and wasteland.Origin: Introduced from South America (or possibly Eurasia)Flowers: May-July

Lepidiumdraba – heart-podded hoarycress, hoary pepperwortDistribution: Occurring chiefly east of the Cascades crest in Washington; widely distributed throughout much of North America.Habitat: Widespread weed in lowlands.Origin: Introduced from EurasiaFlowers: April-August

Lepidiumheterophyllum – Smith's pepperwortDistribution: West of the Cascades in Washington; British Columbia south to California; in scattered locations in eastern U.S.Habitat: Roadsides, pastures, and other disturbed ground.Origin: Introduced from EuropeFlowers: May-June

Lepidiumlatifolium – dittander, broad-leaved peppergrass, broad-leaved pepperwortDistribution: Chiefly east of the Cascades in Washington but also found in the western lowlands; widely distributed throughout central and western North America.Habitat: Moist areas and irrigated land, but also on drier areas.Origin: Introduced from EurasiaFlowers: June-September

Lepidiumnitidum – shining peppergrassDistribution: Known from Klickitat County in Washington; Washington south to California.Habitat: Dry, open areas at low elevation.Origin: NativeFlowers: March-April

Lepidiumoxycarpum – forked pepperwort, sharpfruited pepperwortDistribution: Chiefly in south-central California, rare in the Pacific Northwest.Habitat: Usually on saline soil.Origin: NativeFlowers: March - May

Lepidiumperfoliatum – clasping-leaved peppergrass, round-leaved peppergrass, yellow-flowered peppergrass, clasping peppergrass pepperwortDistribution: Chiefly east of the Cascades in Washington; widely distributed throughout North America.Habitat: Disturbed areas, such as overgrazed land and waste areas, usually where dry.Origin: Introduced from EurasiaFlowers: March-June

Lepidiumramosissimum – branched peppergrass, dull peppergrassDistribution: Chiefly east of the Cascades in Washington; widely distributed throughout much of western and northern North America.Habitat: Sagebrush, ponderosa pine forest openings, roadsides, fields, and other disturbed open areas.Origin: NativeFlowers: June-August

Lepidiumsativum – garden cress pepperwortOrigin: Introduced from western AsiaFlowers: April - June

Leptarrhenapyrolifolia – pearleaf, leatherleaf saxifrageDistribution: Alaska to Oregon, east to Alberta and Montana; in the Olympics and Cascades of WashingtonHabitat: Streambanks, seeps and wet meadows, mid- to high elevations in the mountainsOrigin: NativeFlowers: June - August

Leptosiphonbolanderi – Bolander's desert-trumpets, Baker's linanthusDistribution: Near the east base of the Cascades in Klickitat County, Washington, and in the Sierra Nevada and Coast Range of California.Habitat: Dry, open places at lower elevations, often on serpentine.Origin: NativeFlowers: April-May

Leptosiphonharknessii – three-seed desert-trumpets, Harkness' linanthusDistribution: Occurring east of the Cascades crest in Washington; Washington south to California, east to Utah.Habitat: Drier open places, foothills to mid-elevations in the mountains.Origin: NativeFlowers: June-August

Leptosiphonnuttallii – Nuttall's linanthusDistribution: In the Cascade and Blue Mountains of Washington; Washington south to California, east to Montana, Colorado and New Mexico.Habitat: Open rocky slopes at mid- to high elevations in the mountains.Origin: NativeFlowers: June-August

Leptosiphonseptentrionalis – northern desert-trumpets, northern linanthusDistribution: Occurring east of the Cascades crest in Washington; British Columbia south to California, east to northern Rocky Mountains and Great Plains.Habitat: In seasonally wet open plains and slopes from low to moderate elevations.Origin: NativeFlowers: May-July

Lewisiacolumbiana – Columbia lewisiaDistribution: Occurring on both sides of the Cascades crest in Washington; British Columbia south to California, east to Idaho and Montana.Habitat: Open gravelly or rocky slopes and rock crevices at mid- to high elevations in the mountains.Origin: NativeFlowers: May-August

Lewisianevadensis – Nevada bitterrootDistribution: Olympic and Cascade Mountains of Washington, south to California.Habitat: Open, often gravelly, moist to mesic areas at moderate elevations in the mountains to above tree line.Origin: NativeFlowers: Late May - August

Lewisiapygmaea – least, alpine lewisia, dwarf lewisiaDistribution: Occurring in the Olympic and Cascade Mountains of Washington; British Columbia south to California, east to the Rocky Mountains.Habitat: Open, often gravelly, moist to rather dry areas, mid- to high elevations in the mountains.Origin: NativeFlowers: May-August

Lewisiarediviva – bitterrootDistribution: Occurring east of the Cascades crest in Washington; southern British Columbia south to California, east to Montana, Wyoming, Utah, and Colorado.Habitat: Open gravelly and rocky areas from sagebrush plains to moderate elevations in the mountains.Origin: NativeFlowers: April-June

Lewisiatriphylla – three leaf bitterroot, three leaf lewisiaDistribution: Occurring chiefly east of the Cascades crest in Washington; Washington to California, east to Montana and south in the Rocky Mountains.Habitat: Open, usually sandy areas where vernally moist, ponderosa pine forests to subalpine meadows.Origin: NativeFlowers: May-August

Leymuscinereus – Great Basin lyme grassDistribution: East of the Cascades in Washington; central and western North America.Habitat: Sagebrush-steppe, arid grasslands, forest edges, and other dry, open areas in the intermountain west.Origin: NativeFlowers: June-July

Ligusticumcanbyi – Canby's wild lovageDistribution: On both sides of the Cascades crest in Washington; east to Montana and Wyoming, south to Oregon.Habitat: Wet to somewhat dry soil, from montane to subalpine and alpine areas.Origin: NativeFlowers: May-August

Ligusticumgrayi – Gray's lovage, sheep wild lovageDistribution: Widely distributed throughout the mountain regions of Washington; east to Idaho, south to California and Nevada.Habitat: Moist or sometimes dry open slopes and drier meadows in subalpine and alpine areas.Origin: NativeFlowers: July-September

Ligustrumvulgare – common privetDistribution: Occurring west of the Cascades in Washington; British Columbia south to Texas, east to the Atlantic CoastHabitat: At low elevations in forest understory, forest and prairie edges, and disturbed areas.Origin: IntroducedFlowers: April-May

Lilaeopsisoccidentalis – western grasswort, western lilaeopsisDistribution: Southern Vancouver Island to California, including the Puget Sound region.Habitat: Marshes, salt flats, muddy or sandy beaches and shores along and near the coastOrigin: NativeFlowers: June - July

Liliumcolumbianum – Columbian lilyDistribution: Widely distributed throughout Washington; British Columbia south to California, east to Idaho.Habitat: Prairies, woods and coniferous forests, sea level to mid-elevations in drier areas.Origin: NativeFlowers: May-August

Limnobiumlaevigatum – frogbitDistribution: Known from Pacific County in Washington; also known from California and eastern U.S.Habitat: Lowland ponds, where found floating on water's surface.Origin: IntroducedFlowers: June-September

Limosellaaquatica – awl-leaf mudwortDistribution: Widespread in the Northern Hemisphere; found throughout the Pacific Northwest.Habitat: In shallow water or wet mud, in the valleys and plains.Origin: NativeFlowers: June - October

Linanthuspungens – prickly phloxDistribution: Occurring east of the Cascades crest in Washington; British Columbia south to Baja California, east to Montana and New Mexico.Habitat: Dry, open, sandy or rocky places, from the deserts and plains to moderate elevations in the drier mountains.Origin: NativeFlowers: May-July

Linariapurpurea – purple toadflaxDistribution: Introduced as an ornamental, occasionally escaping west of the Cascades in Washington.Habitat: Bare and disturbed ground.Origin: Introduced from MediterraneanFlowers: June - August

Linderniadubia – false pimpernelDistribution: Occurring on both sides of the Cascades crest in Washington; widely distributed throughout North America.Habitat: Disturbed, open soil, often where moist near ponds, lakes, and streams, from low to middle elevations.Origin: NativeFlowers: May-October

LinnaeaborealisDistribution: In the forests and mountains throughout Washington; Alaska south to California, east in North America to the Atlantic Coast.Habitat: Open to rather dense woods, low to mid-elevations in the mountains.Origin: NativeFlowers: June-September

Linumlewisii – wild blue flaxDistribution: Occurring chiefly east of the Cascades crest in Washington; widely distributed throughout much of western North America.Habitat: Dry, open areas from prairies to alpine ridges.Origin: NativeFlowers: May-July

Liparisloeselii – fen orchid, Loesel's twaybladeDistribution: Occasional, Saskatchewan to Nova Scotia, south to North Dakota and Iowa; Klickitat and Yakima Counties in Washington.Habitat: Around springs and in bogs.Origin: NativeFlowers: July - August

Lipocarphaaristulata – halfchaff sedgeDistribution: Occurring along the Columbia River in central and south-central Washington; Washington to California and Arizona, east in Great Plains and central U.S.Habitat: sandy soils of shorelines, stream banks, ponds, and ditches.Origin: NativeFlowers: June-August

Lithophragmaglabrum – bulbiferous prairie star, bulbous woodlandstarDistribution: East of the Cascades in Washington; British Columbia to California, east to the Dakotas and Colorado.Habitat: Grasslands and sagebrush desert to ponderosa pine and Douglas fir forests.Origin: NativeFlowers: March-May

Lithophragmaparviflorum – small-flowered prairie starDistribution: Widely distributed throughout Washington; British Columbia south to California, east to the Rocky Mountains and Great Plains.Habitat: Prairies, sagebrush desert and forest openings, sea level to mid-elevations in the mountains.Origin: NativeFlowers: March-June

Lithophragmatenellum – slender woodlandstarDistribution: East side of the Cascades in Washington; British Columbia south to California, east to the Rocky Mountain states.Habitat: Sagebrush desert and ponderosa pine forests.Origin: NativeFlowers: May-June

Lithospermumruderale – western gromwell, Columbian puccoon, western stoneseedDistribution: Common east of the Cascades in southern British Columbia, Washington and OregonHabitat: Shrub-steppe to open, dry areas in the mountains at mid-elevationsOrigin: NativeFlowers: April - June

Lloydiaserotina – alpine lilyDistribution: In the Olympic and Cascade mountains of Washington; Alaska south to Oregon, east to Montana and Alberta, and south in the Rockies to New Mexico.Habitat: Gravelly ridges, cliffs and rock crevices at high elevations.Origin: NativeFlowers: June-September

Lobeliadortmanna – water lobeliaDistribution: West of the Cascades in Washington; Vancouver Island and adjacent mainland in British Columbia, south to the Cascades of northern Oregon.Habitat: In shallow water at the margins of ponds and lakes.Origin: NativeFlowers: June-August

Lobulariamaritima – sweet alison, sweet alyssumDistribution: Occurring in scattered locations across Washington; British Columbia south to Texas; also occurring throughout central and eastern North America.Habitat: Escaping from cultivation to roadsides, pastures, and other disturbed areas, often where moist.Origin: Introduced from the western MediterraneanFlowers: April-August

Loliummultiflorum – annual ryegrass, Italian ryegrass, perennial ryegrassDistribution: Introduced and well established in much of temperate North America.Habitat: Roadsides and waste ground.Origin: IntroducedFlowers: May - July

Loliumperenne – English ryegrass, perennial ryegrassDistribution: Commonly cultivated as a forage plant; escaped and well established in the Pacific Northwest.Habitat: Old fields, roadsides, and waste places.Origin: IntroducedFlowers: May - July

Lomatiumambiguum – streambank desert-parsley, swale desert-parsley, lacy lomatiumDistribution: Chiefly east of the Cascades in Washington; southern British Columbia south to northeast Oregon, east to western Montana.Habitat: Open, often rocky slopes and flats, from the foothills to moderate elevations in the mountains.Origin: NativeFlowers: May-July

Lomatiumbradshawii – Bradshaw's desert-parsleyDistribution: Willamette Valley of Oregon from near Salem to near Eugene.Habitat: Low, moist ground.Origin: NativeFlowers: May

Lomatiumbrandegeei – Brandegee's desert-parsleyDistribution: Chiefly east of the Cascades in Washington;Habitat: Open to wooded slopes, moderate to fairly high elevations in the mountains; southern British Columbia south to Washington.Origin: NativeFlowers: May-July

Lomatiumcanbyi – chucklusa, Canby's desert-parsleyDistribution: Along Columbia River in NE Washington, common from Kittitas County south into OregonHabitat: Scablands and sagebrush steppe in rather deep soilOrigin: NativeFlowers: March - April

Lomatiumcolumbianum – Columbia Gorge desert-parsleyDistribution: At the east end of the Columbia River Gorge in Washington; Washington south to northern Oregon.Habitat: Deeper soil in shrub-steppe.Origin: NativeFlowers: March-April

Lomatiumcous – cous, cous-root desert-parsleyDistribution: Southeast Washington and northeast Oregon,east through Idaho to Montana and WyomingHabitat: Dry, open, often rocky places often with sagebrush; common at low elevations, occasionally found much higherOrigin: NativeFlowers: April - July

Lomatiumdissectum – fern-leaved desert parsleyDistribution: Chiefly west of the east base of the Cascades, British Columbia to CaliforniaHabitat: Open areas from the foothills to moderate elevations in the mountainsOrigin: NativeFlowers: April - June

Lomatiumfarinosum – Hamblen's lomatiumDistribution: Chelan to Yakima Counties, Washington, east to Montana.Habitat: Rocky slopes and scablands, often on lithosol and with sagebrush.Origin: NativeFlowers: April - May

Lomatiumgeyeri – Geyer's desert-parsleyDistribution: Chiefly east of the Cascades in Washington; southern British Columbia south to Washington, east to Idaho.Habitat: Deeper soil in low to mid-elevations of open, dry areas, and under Ponderosa pine.Origin: NativeFlowers: March-May

Lomatiumgormanii – Gorman's desert-parsley, salt and pepperDistribution: East of the Cascades in Washington; Washington south to Oregon, east to Idaho.Habitat: Open slopes and scablands in the foothills, valleys and plains, often with sagebrush.Origin: NativeFlowers: March-May

Lomatiumlaevigatum – slickrock desert-parsley, smooth lomatiumDistribution: Along the Columbia River in Klickitat County, Washington, and adjacent Oregon.Habitat: Crevices is basalt cliffs.Origin: NativeFlowers: April

Lomatiumlinearifolia – Great Basin Indian-potato, linear-leaved orogeniaDistribution: Eastern Washington and Oregon, southeast to ColoradoHabitat: Open slopes and ridges, low to mid-elevationsOrigin: NativeFlowers: March - May

Lomatiummacrocarpum – large-fruit desert-parsley, bigseed lomatiumDistribution: East of the Cascades in Washington; British Columbia south to California, east to North Dakota, Wyoming and Utah.Habitat: Open, dry, rocky areas at low elevations.Origin: NativeFlowers: March-May

Lomatiummartindalei – Cascade desert-parsley, coast range lomatiumDistribution: Distributed on both sides of the Cascades in Washington; British Columbia south to Oregon.Habitat: Dry mountain meadows, often rocky areas.Origin: NativeFlowers: May-September

Lomatiummultifidum – fern-leaved desert parsleyDistribution: East of the Cascades, British Columbia to Oregon, east to WyomingHabitat: Open, often rocky slopes and dry meadows, low to mid-elevationsOrigin: NativeFlowers: April - June

Lomatiumnudicaule – Indian-consumption-plant, barestem lomatium, pestle parsnipDistribution: Occurring on both sides of the Cascades crest in Washington; British Columbia south to California, east to Idaho and Utah.Habitat: Dry, open areas; common in shrub-steppe, but found in mountain meadows.Origin: NativeFlowers: April-June

Lomatiumpapilioniferum – butterfly bearing biscuitroot, butterfly bearing lomatiumDistribution: Occurring east of the Cascades crest from central Washington southward; southern British Columbia to California, east to Idaho and Nevada.Habitat: Sagebrush desert and open slopes at low to moderate elevations.Origin: NativeFlowers: April-June

Lomatiumpiperi – Piper's lomatiumDistribution: East of the Cascades in Washington; central Washington south to northern California.Habitat: Sagebrush-bunchgrass steppe up to ponderosa pine forests.Origin: NativeFlowers: April-June

Lomatiumrollinsii – Rollins' desert-parsleyDistribution: Canyons of the Snake and lower Salmon Rivers, eastern Oregon and western Idaho.Habitat: Open slopes.Origin: NativeFlowers: April

Lomatiumroneorum – RoneDistribution: Currently known only from Chelan County and thought to be endemic to there.Habitat: Open, rocky slopes in Ponderosa pine forest.Flowers: April-June

Lomatiumsalmoniflorum – Salmon River desert-parsleyDistribution: Near the Snake and Clearwater Rivers in Idaho, Latah and Nez Perce Counties, Idaho, and Whitman County west to Palouse Falls, Washington.Habitat: Open, rocky slopes.Origin: NativeFlowers: March - April

Lomatiumserpentinum – Snake Canyon desert-parsleyDistribution: Near the Snake River Canyon, western Idaho, eastern Oregon and extreme southeast Washington.Habitat: Open, often rocky slopes.Origin: NativeFlowers: April - July

Lomatiumsimplex – nine-leaf biscuit-rootDistribution: East of the Cascades in Washington; widely distributed east of the Continental Divide in Montana south to Colorado.Habitat: Dry, open areas at low elevations.Origin: NativeFlowers: March-May

Lomatiumtriternatum – triternate biscuit-rootDistribution: Occurring chiefly east of the Cascades crest in Washington; British Columbia south to California, east to the Rocky Mountains.Habitat: Dry to somewhat moist open areas, low to mid-elevations.Origin: NativeFlowers: April-July

Lomatiumwatsonii – Watson's desert-parsleyDistribution: Soluthern Kittitas County, south through Yakima and Klickitat Counties, to northcentral Oregon.Habitat: Open hillsides, often with sagebrush.Origin: NativeFlowers: May

Loniceraciliosa – orange honeysuckleDistribution: Ranging throughout Washington; British Columbia south to Oregon, east to Montana.Habitat: Open to rather dense woods, low to mid-elevations in the mountains.Origin: NativeFlowers: May-July

Loniceraconjugialis – purple-flower honeysuckleDistribution: Mt. Adams south chiefly through the east side of the Cascades in Washington; south to the Sierra Nevada of California.Habitat: In woods, meadows and moist open slopes at mid-elevations in the mountains.Origin: NativeFlowers: June-July

Loniceraetrusca – Etruscan honeysuckleDistribution: Occasional west of the Cascades in Washington; established along the Oregon coast and southern British Columbia.Habitat: Thickets and waste areas.Origin: IntroducedFlowers: June-August

Lonicerahispidula – hairy honeysuckleDistribution: West of the Cascades in Washington; British Columbia to Oregon.Habitat: Open woods at low elevations.Origin: NativeFlowers: June-August

Lonicerainvolucrata – bearberry honeysuckle, black twin-berryDistribution: Both sides of the Cascades in Washington; Alaska south to California, east to Montana and New Mexico.Habitat: Common in open woods at low to mid-elevations.Origin: NativeFlowers: April-August

Lonicerajaponica – Japanese honeysuckleDistribution: Occasionally escaped from cultivation in lowland western Washington; California east through the midwestern, southeastern, and northeastern U.S.Habitat: Disturbed areas, woods, and thickets.Origin: IntroducedFlowers: May-July

Loniceratatarica – Tartarian honeysuckleDistribution: Scattered localities throughout Washington; throughout much of North America except the southeastern U.S.Habitat: Disturbed areas, woods, and thickets.Origin: Introduced from EurasiaFlowers: May-July

Lonicerautahensis – Rocky Mountain honeysuckle, Utah honeysuckleDistribution: Both sides of the Cascades in Washington; British Columbia to Oregon, east to Montana and south in the Rockies to Arizona.Habitat: Mid- to high elevations in the mountains.Origin: NativeFlowers: May-July

Lotuscorniculatus – garden bird's-foot-trefoilDistribution: Occurring on both sides of the Cascades in Washington; widely distributed throughout most of North America.Habitat: Mesic to wet areas, typically where disturbed.Origin: IntroducedFlowers: May-September

Lotusuliginosus – big lotus, big trefoil, large trefoilDistribution: West of the Cascades in Washington; British Columbia south to California, east to Idaho; east across Canada to Nova Scotia; scattered localities in eastern U.S.Habitat: Moist to wet disturbed areas, roadsides, abandoned lots, and coastal tidelands.Origin: IntroducedFlowers: May-July

Ludwigiahexapetala – false loosestrife, water primroseDistribution: Scattered locations throughout Washington; along Columbia River near Portland, OR, introduced in much of North America.Habitat: Swamps, lakes, and streams.Origin: Introduced from South AmericaFlowers: June-August

Ludwigiapalustris – marsh primrose-willowDistribution: West side of the Cascades and along the Columbia River in Washington; widespread in North America, Africa and Eurasia.Habitat: Marshes and bogs.Origin: NativeFlowers: July-September

Luetkeapectinata – lutkea, partridgefootDistribution: Occurring in the Olympics and Cascades mountains in Washington; Alaska south to California, and in the Rocky Mountains.Habitat: Usually on sandy soil in moist or shady places, subalpine to alpine.Origin: NativeFlowers: June-August

Luinahypoleuca – littleleaf luina, silverback luina, littleleaf silverbackDistribution: In the Olympic and Cascade mountains in Washington; British Columbia south to California.Habitat: Open, rocky areas, moist to somewhat dry, moderate to high elevations in the mountains.Origin: NativeFlowers: June-October

Lunariaannua – honesty, money plantDistribution: Distributed in scattered locations across Washington; British Columbia south to California and Utah; also distributed throughout eastern North America.Habitat: Escaping from cultivation to urban forests, roadsides, and other disturbed areas.Origin: Introduced from southeast EuropeFlowers: March-June

Lupinusalbicaulis – sicklekeel lupineDistribution: Chiefly west of the Cascades in Washington; Washington south to California.Habitat: Grasslands and prairies from the lowlands to moderate elevations.Origin: NativeFlowers: May-July

Lupinusarboreus – tree lupine, yellow-bush lupineDistribution: Occurring in the western Washington lowlands and along the Pacific coast; British Columbia south to California.Habitat: Sandy soil.Origin: IntroducedFlowers: May-September

Lupinusarbustus – silvery lupine, spurred lupineDistribution: East of the Cascades crest in Washington; British Columbia south to California, east to Montana and Utah.Habitat: Sagebrush deserts and ponderosa pine forest openings.Origin: NativeFlowers: May-July

Lupinusargenteus – silvery lupineDistribution: Chiefly east of the Cascades in Washington; British Columbia south to California, east to the Dakotas and New Mexico.Habitat: Ponderosa pine forests to subalpine ridges.Origin: NativeFlowers: May-July

Lupinusbicolor – small-flower lupine, two-color lupineDistribution: Chiefly west of the Cascades in Washington, but also in southeastern part of state; British Columbia south to California, east to Arizona.Habitat: Open meadows, grasslands, prairies, and sandy riverbanks at low to moderate elevations.Origin: NativeFlowers: April-July

Lupinuslatifolius – broadleaf lupineDistribution: In the Olympic and Cascade mountains of Washington; British Columbia south to California.Habitat: Chiefly in forest openings at mid-elevation to subalpine meadows.Origin: NativeFlowers: June-August

Lupinuslepidus – prairie lupineDistribution: Widely distributed throughout Washington; Alaska south to California, east to the Rocky Mountains.Habitat: Open areas from low elevations to the alpine.Origin: NativeFlowers: June-August

Lupinusleucophyllus – velvet lupineDistribution: Occurring east of the Cascades crest in Washington; British Columbia south to California, east to Montana, Wyoming, and Colorado.Habitat: Shrub-steppe and ponderosa pine forests.Origin: NativeFlowers: June-August

Lupinusmicrocarpus – chick lupineDistribution: Chiefly west of the Cascades in Washington, though also known from east of Cascades; British Columbia south to California.Habitat: Coastal bluffs, grassy balds, and other dry, open areas at low elevations.Origin: NativeFlowers: April-June

Lupinusoreganus – Oregon lupineDistribution: West of the Cascades in Washington; south to Willamette Valley in Oregon.Habitat: Moist to dry areas of prairies and openings in oak woodlands.Origin: NativeFlowers: April-June

Lupinuspusillus – low lupine, rusty lupineDistribution: Occurring east of the Cascades crest in south-central Washington; Washington south to California, east to the Rocky Mountains and Great Plains of Canada and the U.S.Habitat: Shrub-steppe habitat, often where sandy.Origin: NativeFlowers: May-June

Lupinusrivularis – river-bank lupineDistribution: Occurring on both sides of the Cascades crest in Washington; British Columbia south to California.Habitat: Gravelly prairies, open woods and river banks at low elevations.Origin: NativeFlowers: April-September

Lupinussaxosus – rock lupineDistribution: Occurring east of the Cascades crest in Washington; Washington south to California, east to Idaho and Nevada.Habitat: Shrub-steppe habitat.Origin: NativeFlowers: April-May

Lupinussericeus – silky lupineDistribution: Occurring chiefly east of the Cascades crest in Washington; British Columbia south to Oregon, east to Alberta and south to Arizona.Habitat: Sagebrush deserts to forest openings at moderate elevations.Origin: NativeFlowers: May-August

Lupinussulphureus – sulfur lupineDistribution: Occurring east of the Cascades crest in Washington; British Columbia south to California.Habitat: Shrub-steppe, grassland, and open ponderosa pine forests.Origin: NativeFlowers: April-June

Luzulaarcuata – curved woodrushDistribution: Alaska, British Columbia, and Mt. Rainier, Washington.Habitat: Rocky or gravelly soil, usually on moraines or above timberline.Origin: NativeFlowers: July - August

Luzulahitchcockii – Hitchcock's woodrush, smooth woodrushDistribution: Occurring on both sides of the Cascades crest in Washington; southern British Columbia south to Crater Lake and the Wallowa Mountains of Oregon, east to Alberta, Idaho and Montana.Habitat: Montane forests to alpine slopes, ridges and meadows.Origin: NativeFlowers: July-September

Luzulamultiflora – common woodrushDistribution: Occurring on both sides of the Cascades crest in Washington; Alaska south to Oregon, east to Alberta and western Montana; also in northeastern United States.Habitat: Fields, meadows, open woods and clearings, at low to moderate elevations in the mountains.Origin: NativeFlowers: May-July

Luzulaparviflora – small flowered woodrushDistribution: Alaska to Newfoundland, south to southern California and New York.Habitat: Moist to fairly dry areas, coastal rain forest to alpine slopes.Origin: NativeFlowers: May - August

Lychniscoronaria – rose campionDistribution: Occurring chiefly west of the Cascades crest in Washington; British Columbia south to California, east to Idaho and Utah; eastern North America.Habitat: Along roadways, railways and waste land.Origin: IntroducedFlowers: June-August

Lyciumbarbarum – matrimony-vineDistribution: Chiefly east of the Cascades in Washington; widely distributed throughout North America.Habitat: Disturbed ground.Origin: Introduced from EurasiaFlowers: June-September

Lycopodiellainundata – bog clubmoss, marsh clubmoss, northern bog clubmossDistribution: Occurring west of the Cascades crest in Washington; Alaska south to California; in scattered locations in north central Canada; from Minnesota and Ontarioa east to the Atlantic Coast.Habitat: Wet areas, pond and lakeshores from low to middle elevations in the mountains.Origin: Native

Lycopodiumclavatum – common clubmoss, elk-moss, stag, ground pine, running pineDistribution: Both sides of the Cascades in Washington; British Columbia south to California in western North America; circumboreal.Habitat: Moist coniferous woods and swamps.Origin: NativeSpores: Produces spores April-October

Lycopusamericanus – cut-leaf water-horehoundDistribution: Both sides of the Cascades in Washington; throughout most of North America.Habitat: Nonalkaline wetland, riparian, pond and lakeshore sites at low to moderate elevations.Origin: NativeFlowers: June-August

Lycopusasper – rough water-horehoundDistribution: Chiefly east of the Cascades; southern British Columbia to California, east to Colorado and Minnisota.Habitat: Marshes and shores of streams and lakes; tolerant of alkali.Origin: NativeFlowers: June-August

Lycopusuniflorus – northern bugleweedDistribution: Both sides of the Cascades in Washington; Alaska to Newfoundland, south to northwest California and North Carolina.Habitat: Stream banks, marshes and peat bogs, mostly in the mountains, but descending to sea level west of the Cascades.Origin: NativeFlowers: July-September

Lygodesmiajuncea – rush skeletonplantDistribution: Known from Spokane County in Washington; southeastern British Columbia to eastern Washington, Idaho and Nevada, east to Great Plains and Great Lakes region.Habitat: Dry, open places, often in sandy soil.Origin: NativeFlowers: June-September

Lysichitonamericanus – skunk cabbage, yellow skunk cabbageDistribution: Both sides of the Cascades in Washington; Alaska south to California.Habitat: Swampy areas from sea level to mid-elevations in the mountains.Origin: NativeFlowers: April-July

Lysimachiaarvensis – scarlet pimpernelDistribution: Scattered locations on both sides of the Cascades in Washington; widely distributed throughout North America.Habitat: Weed of disturbed open areas, waste ground.Origin: IntroducedFlowers: May-June

Lysimachiaeuropaea – arctic starflower, northern starflowerDistribution: Both side of the Cascades in Washington; Alaska south to California, east to Alberta and Idaho.Habitat: Bogs and swamps, low to mid-elevations in the mountains.Origin: NativeFlowers: May-August

Lysimachialatifolia – broad-leaved starflower, western starflowerDistribution: Occurring on both sides of the Cascades crest in Washington; Yukon Territory south to California, east to Idaho.Habitat: Woods and prairies, low to moderate elevations in the mountains.Origin: NativeFlowers: March-July

Lysimachiamaritima – sea milkwort, sea-milkwortDistribution: Chiefly west of the Cascades in Washington; circumboreal; Alaska to California, east to Newfoundland, south in eastern North America to Virginia.Habitat: Coastal tideflats and saline areas.Origin: NativeFlowers: April-June

Lysimachiaminima – chaffweedDistribution: Chiefly east of the Cascades in Washington, though also found near the coast; throughout much of North America.Habitat: Moist ground and vernal pools at low elevations.Origin: NativeFlowers: May-June

Lysimachianummularia – creeping-JennyDistribution: Scattered locations west of the Cascades in Washington; British Columbia south to California and Nevada; occurring in central U.S and eastern North America.Habitat: Moist, disturbed ground along lakes, ponds, roadsides and near gardens.Origin: IntroducedFlowers: June-August

Lysimachiapunctata – large yellow-loosestrifeDistribution: Scattered localities across Washington; British Columbia south Oregon, east to Montana; scattered throughout central and eastern North America.Habitat: Old fields, roadsides and stream banks.Origin: IntroducedFlowers: July-August

Lysimachiaterrestris – swampcandlesDistribution: Along the coast in Washington; British Columbia south to Oregon and Idaho; native and abundant in central and eastern North America.Habitat: Cultivated cranberry bogs, and swamps.Origin: Introduced from eastern North AmericaFlowers: June-August

Lysimachiathyrsiflora – tufted yellow-loosestrifeDistribution: Distributed on both sides of the Cascades in Washington; Alaska south to California, eastern North America.Habitat: Swamps, lakes and ditches.Origin: NativeFlowers: May-July

Lysimachiavulgaris – garden yellow-loosestrifeDistribution: Occurring in scattered localities on both sides of the Cascades in Washington; British Columbia to Oregon, east to Montana; widely distributed in eastern North America.Habitat: Uncommon garden escape of moist areas, lake and pond margins, and riparian zones.Origin: Introduced from EuropeFlowers: June-August

Lythrumhyssopifolia – hyssop loosestrifeDistribution: Scattered locations on both sides of the Cascades in Washington; British Columbia south to California; eastern North America.Habitat: Moist, disturbed areas.Origin: IntroducedFlowers: May-September

Lythrumportula – spatula-leaf loosestrifeDistribution: Chiefly west of the Cascades in Washington; British Columbia south to California.Habitat: Wetlands, disturbed moist areas.Origin: IntroducedFlowers: June-September